It seems this is caused by a bug in eglibc. This bug has been fixed in v2.12 but Ubuntu Lucid ships v2.11.1.
2010-02-24 Ulrich Drepper <email address hidden> [BZ #5553] * malloc/malloc.c (public_vALLOc): Set ar_ptr when trying main_arena. (public_pVALLOc): Likewise. Patch by Petr Baudis.
Maybe this patch could be applied to the Ubuntu Lucid package?
It seems this is caused by a bug in eglibc. This bug has been fixed in v2.12 but Ubuntu Lucid ships v2.11.1.
2010-02-24 Ulrich Drepper <email address hidden>
[BZ #5553]
* malloc/malloc.c (public_vALLOc): Set ar_ptr when trying main_arena.
(public_pVALLOc): Likewise.
Patch by Petr Baudis.
Maybe this patch could be applied to the Ubuntu Lucid package?